Magnetic and/or electrostatic pivot

ABSTRACT

A method for orienting a timepiece component including ferromagnetic material, where, on both ends of this component, two magnetic fields each attract it onto a pole piece, with an unbalance in the intensity of these fields around this component, in order to create a differential in the forces thereon and to press one of these ends onto a contact surface of one of the pole pieces, and to hold the other end at a distance from the other pole piece. A magnetic pivot includes such a component with two ends. It includes a guide device with surfaces of two pole pieces each generating a magnetic field attracting one of these ends, the magnetic forces exerted on the two ends being of different intensity, in order to attract only one end into contact with only one of these pole piece surfaces.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Ser. No. 13/290,544 filed Nov.7, 2011, the entire content of which is incorporated herein byreference, and claims the benefit of priority under 35 U.S.C. 119 toEuropean Application No. 10190510.7 filed Nov. 9, 2010.

FIELD OF THE INVENTION

The invention concerns a method of orienting a timepiece component toguide the pivoting of said component, which is made of material that isat least partially magnetically permeable or at least partiallymagnetic, and/or of material that is at least partially conductive orrespectively at least partially electrized, wherein said component ispivotally mounted in a chamber between a first end and a second end ofsaid component.

The invention also concerns a device for guiding the pivoting of atimepiece component, which is made of material that is at leastpartially magnetically permeable or at least partially magnetic, and/orof material that is at least partially conductive or at least partiallyelectrized, at a first end and at a second end.

The invention also concerns a magnetic and/or electrostatic pivotincluding a timepiece component, made of a material that is at leastpartially magnetically permeable or at least partially magnetic at afirst end and at a second end, or respectively at least partiallyconductive or at least partially electrized at a first end and at asecond end.

The invention also concerns a timepiece movement including at least onedevice of this type for pivotal guiding, and/or at least one magneticand/or electrostatic pivot of this type.

The invention further concerns a timepiece including at least onetimepiece movement of this type and/or at least one device of this typefor pivotal guiding, and/or at least one magnetic and/or electrostaticpivot of this type.

The invention concerns the field of micro-mechanics and in particularhorology, to which it is particularly well suited.

BACKGROUND OF THE INVENTION

Micro-mechanics, and in particular horological technique, useconventional solutions for positioning the axis or the arbour of acomponent, based on mechanical friction.

In the particular application to a pivoting component incorporated in awatch movement, or in an oscillator, a recurring problem lies in thestrong dependence of the efficiency and/or quality factor of thecomponent on the position of the watch in which said component isincorporated. In particular, the efficiency and/or quality factor isconsiderably lower when a watch is in a vertical position. The solutionsproposed for overcoming this problem often give preference to areduction in the efficiency and/or quality factor in the horizontalposition rather than an increase in the efficiency and/or quality factorin the vertical position.

The problems to be solved are thus as follows:

-   -   Making efficiency and/or the quality factor equal in all        positions of the watch.    -   Increasing efficiency and/or the quality factor in all        positions.

DE Patent 12 11 460 in the name of SIEMENS AG is known, which disclosesa mobile component, formed by a pin integral with an internal tubularmagnet, inserted into an external tubular magnet. The external tubularmagnet can move inside a cartouche, coaxial to the two magnets, againsta support surface in abutment at one end, and against a spring held by abush at the other end. This mobile component is also axially guided on aspindle integral with the bush. At each axial end, the mobile componentincludes a protective sleeve for the fragile ceramic core formed by theinternal magnet. The means for guiding pivoting is formed by thecooperation between the two internal and external tubular magnets.However, the holding of the mobile component on the first magnetic polepiece is not equivalent to a support since there is a connection betweenthis mobile component and the internal tubular magnet, via a flange andone of the two sleeves. Consequently, the mobile component of thisPatent is not free relative to the first magnetic pole piece formed bythe internal magnet, but only relative to the second magnetic polepiece, formed by the external magnet.

DE Patent Application No. 198 54 063 A1 in the name of VLADIMIR JAGMANNdiscloses a mobile component, made of magnetisable material, placed inan air gap between two magnetic pole pieces generating a magnetic fieldin a direction perpendicular to the gravitational force of attraction,shorter than the air gap, resting on only one of the magnetic polepieces, and being semi-levitated in proximity to the other magnetic polepiece. The pivot axis of the mobile component coincides with an axisdefined by the poles of the two pole pieces.

DE Patent No. 12 20 224 B in the name of KERN & CO AG discloses, in asimilar manner, a mobile component pivoting in the same way, with nofriction in a field between two magnets. The two magnets have convexradiating ends made of hard material. The surface of the mobilecomponent abutting on one of these radiating ends is also convex andradiated.

FR Patent No 1 115 966 A in the name of JUNHANS GEB AG discloses aregulator with a rotating balance, and uses static magnetic fields toreduce the effect of the weight of the oscillating member.

DE Patent No 1 734 590 in the name of Friedrich Mauthe GmbH alsodiscloses a magnetic device for lightening the load on a pivot.

GB Patent No 739 979 A in the name of ROULEMENTS A BILLES MINIATURESdiscloses a magnetic bearing with a vertical axis for a measuringapparatus such as a galvanometer.

U.S. Pat. No. 3,496,780 A in the name of CLAVELOUX NOEL discloses anelectrostatic suspension for gyroscope rotors obtained with a pluralityof electrodes.

SUMMARY OF THE INVENTION

The invention proposes to overcome the problems of the prior art, byinventing a method for orienting a timepiece component, and morespecifically aligning the component on a pivot axis, allowing frictionto be drastically reduced compared to ordinary mechanical guide devices,and thereby improving the independence of the operating quality of atimepiece movement with respect to the orientation thereof in space.

To achieve this, the invention implements a device for guiding thepivoting of the component, so as to form a magnetic pivot for timepiececomponents providing efficiency and/or a quality factory that isindependent of position.

The invention therefore concerns a method for orienting a timepiececomponent to guide the pivoting of said component, which is made ofmaterial that is at least partially magnetically permeable orrespectively at least partially magnetic, and/or of material that is atleast partially conductive or respectively at least partiallyelectrized, wherein said component is pivotally mounted in a chamberbetween a first end and a second end of said component, characterized inthat, on both sides of said first and second ends, two magnetic orrespectively electrostatic fields are created, each tending to attractsaid component onto a pole piece, and an unbalance is created betweensaid magnetic or respectively electrostatic fields around saidcomponent, so as to create a differential in the forces thereon in orderto press one of said ends of said component onto a contact surface ofone of said pole pieces, and to hold the other of said ends at adistance from a contact surface of the other pole piece, said magneticor respectively electrostatic fields being of different intensity atsaid first end and said second end, and further characterized in thatsaid first pole piece and said second pole piece are distinct from saidcomponent, and are each located at the periphery of or in proximity tosaid chamber, and are each made of material that is at least partiallymagnetic or respectively magnetically permeable, and/or of material thatis at least partially electrized or respectively at least partiallyconductive, and further characterized in that said component is freelymounted in said chamber between said pole pieces so as to rest on asupport surface in proximity to only one of said pole pieces.

The invention therefore also concerns a device for guiding the pivotingof a timepiece component made of material that is at least partiallymagnetically permeable or respectively at least partially magnetic,and/or material that is at least partially conductive or respectively atleast partially electrized, wherein said component is pivotally mountedin a chamber between a first end and a second end of said component,characterized in that it includes, at a greater air-gap distance, by thevalue of a determined operational play, than the distance of centresbetween said first end and said second end, a first surface of a firstpole piece and a second surface of a second pole piece, wherein saidpoles pieces are arranged either each to be attracted by a magnetic orrespectively electrostatic field transmitted by one of said first orsecond ends of said component, or each to generate a magnetic orrespectively electrostatic field attracting one of said first or secondends of said component, such that the magnetic or respectivelyelectrostatic attraction forces being exerted on said component at thetwo ends thereof are of different intensity, so as to attract saidcomponent via one of the said two ends thereof, in direct or indirectcontact onto only one of said surfaces of said pole pieces, wherein saidmagnetic or respectively electrostatic fields are of different intensityat said first end and said second end.

The invention also concerns a magnetic or respectively electrostaticpivot, including a timepiece component made of material that is at leastpartially magnetically permeable or respectively at least partiallymagnetic, and/or of material that is at least partially conductive or atleast partially electrized, wherein said component is pivotally mountedin a chamber between a first end and a second end of said component,characterized in that it includes a device for guiding the pivoting ofsaid timepiece component including, at a greater air-gap distance, bythe value of a determined operational play, than the distance of centresbetween said first end and said second end, a first surface of a firstpole piece and a second surface of a second pole piece, wherein saidpoles pieces are arranged either each to be attracted by a magnetic orrespectively electrostatic field transmitted by one of said first orsecond ends of said component, or each to generate a magnetic orrespectively electrostatic field attracting one of said first or secondends of said component, such that the magnetic or respectivelyelectrostatic attraction forces being exerted on said component at thetwo ends thereof are of different intensity, so as to attract saidcomponent via one of the said two ends thereof, in direct or indirectcontact onto only one of said surfaces of said pole pieces, saidmagnetic or respectively electrostatic fields being of differentintensity at said first end and said second end.

The invention also concerns a timepiece movement including at least onedevice of this type for pivotal guiding, and/or at least one magneticand/or electrostatic pivot of this type.

The invention further concerns a timepiece including at least onetimepiece movement of this type and/or at least one device for pivotalguiding of this type, and/or at least one magnetic and/or electrostaticpivot of this type.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the invention will appear more clearlyupon reading the following detailed description, with reference to theannexed drawings, in which:

FIG. 1 shows a schematic, partial elevation of a device for guiding acomponent according to the invention.

FIG. 2 shows, in a similar manner to FIG. 1, a component forincorporation into a magnetic pivot according to the invention.

FIG. 3 shows, in a similar manner to FIG. 1, a magnetic pivot accordingto the invention including the device of FIG. 1, and the component ofFIG. 2 in a position of stable cooperation.

FIG. 4 shows, in a similar manner to FIG. 1, a magnetic pivot accordingto the invention, revealing the system of forces acting on thecomponent.

FIG. 5 shows, in a similar manner to FIG. 4, the system of forces actingon the component shown in a position that has been made unstable.

FIG. 6 shows, in longitudinal cross-section along the pivot axisthereof, a magnetic pivot according to the invention including a devicefor guiding a component according to the invention, in a firstembodiment.

FIG. 7 shows a similar, schematic view to FIG. 6 of a magnetic pivotaccording to another embodiment.

FIG. 8 shows a schematic, partial and perspective view of a timepieceincluding a movement that incorporates a magnetic pivot according to theinvention, particularly in accordance with the embodiments of FIG. 6 or7.

FIG. 9 shows a component formed by a balance, inserted in a componentguide device according to the invention.

FIG. 10 shows a schematic view of the ratio of forces acting on acomponent.

FIG. 11 shows a diagram of the growth in the resulting magnetic forcedensity as a function of the abscissa along the longitudinal axis ofFIG. 10.

FIG. 12 shows a schematic elevation of a variant of the component guidedevice according to the invention.

FIG. 13 shows a schematic, longitudinal cross-section along a pivot axisof an alternative embodiment of a device according to the invention,provided with a damping device.

FIG. 14 shows a schematic, partial and perspective view of a dampingelement of the variant of FIG. 13.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The invention develops a particular method for orienting a timepiececomponent 1 to guide the pivoting thereof, and, more specifically, foraligning said component on a pivot axis D.

The object of the invention is to provide an alternative to conventionalpivots, and to drastically reduce friction compared to ordinarymechanical guide devices, and thereby improve the independence of theoperating quality of a timepiece movement relative to the orientationthereof in space.

In order to implement this method, the invention further concerns adevice for guiding the pivoting of the component, so as to form amagnetic and/or electrostatic pivot for timepiece components providingefficiency and/or a quality factor that is independent of position.

Owing to certain particular features, which will be set out hereinafter,notably the preferred use of highly intense magnetic and/orelectrostatic forces relative to the force of gravity, the inventionfinds more particular application in the field of micro-mechanics andmore particularly the field of horology, for which it was developed andhas been the subject of operating prototypes. The low mass ofhorological components means very low weight, and, in a mannercompatible with the dimensions of a watch or suchlike, it is possible togenerate magnetic and/or electrostatic fields capable of producing onsaid component forces and/or attraction torques that are at least tentimes greater than the attraction force or torque of gravity. Thus theinvention is described here for this preferred horological application,and can be immediately used in the current state of the art of magnetsand electrets, and can be implemented in the necessary dimensions withthe required magnetic or electrostatic field intensities, without anyparticular development.

The invention proposes to improve the pivoting conditions of acomponent, by reducing friction compared to the prior art, and bypermanently aligning the principle axis of inertia thereof, hereinaftercalled the “longitudinal axis” for the sake of simplicity, on atheoretical pivot axis. Naturally, the invention is also applicable tocomponents which are unbalanced or pivot about a different axis from themain axis of inertia, but the invention provides the greatest advantagesin the preferred case where the main axis of inertia of the componentcoincides with the pivot axis.

In a non-limiting manner, the component may therefore be a balance, asprung balance assembly, an escape wheel, pallets, a gear wheel, aratchet, a click, a lever, a barrel, an automatic winding rotor, a dateor moon phase disc, a hammer, a heart-piece, a column wheel, or anyother component that is usually pivotally moveable.

The invention forms a system of axis-pivots for a component usingmagnetic and/or electrostatic forces.

In the explanation set out hereinafter, “magnetically permeable”materials are materials having a relative permeability comprised between100 and 10000 such as steels, which have a relative permeability closeto 100 for balance staffs, for example, or close to 4000 for the steelscommonly used in electric circuits, or other alloys whose relativepermeability reaches values of 8000 to 10000.

“Magnetic materials”, for example in the case of pole pieces, arematerials able to be magnetised so as to have a remanent field comprisedbetween 0.1 and 1.5 Tesla, such as for example “Neodymium Iron Boron”having a magnetic energy density Em close to 512 kJ/m³ and giving aremanent field of 0.5 to 1.3 Tesla. A lower level of remanent field,towards the bottom part of the range, may be used in the event of thecombination, in a magnetising pair, of a magnetic material of this typewith a magnetically permeable antagonistic component with highpermeability, closer to 10000 within the range of 100 to 10000.

“Paramagnetic” materials are materials with a relative permeabilitycomprised between 1.0001 and 100, for example for connecting piecesinserted between a magnetic material and a magnetically permeableantagonistic component or between two magnetic materials, for example aconnecting piece between a component and a magnetic pole piece.

“Diamagnetic” materials are materials with a relative magneticpermeability of less than 1.

Finally, “soft magnetic” materials, as opposed to “amagnetic” materials,particularly for shields, are materials having high magneticpermeability but high saturation, since they are not required to bepermanently magnetic: they must conduct the field as well as possible,so as to reduce the field external thereto. These components can thenalso protect a magnetic system from external fields. These materials arepreferably chosen to have a relative magnetic permeability of between 50and 200 and with a saturation field of more than 500 Nm.

“Amagnetic” materials are defined as materials with a relative magneticpermeability very slightly greater than 1, and less than 1.0001,typically like silicon, diamond, palladium and similar materials. Thesematerials may generally be obtained via MEMS technology or the LIGAmethod.

In the following description, “conductive” materials are materials whoseresistivity at ambient temperature (T=20° C.) is less than 1 μΩm): forexample, silver, gold and aluminium are excellent conductors. In thefollowing description, “insulating” materials are materials whoseresistivity at ambient temperature is higher than 10,000 MΩm) and whosedielectric rigidity is greater than 10 kV/mm: for example vitreous orplastic materials are generally good insulators.

In order to be able to guarantee a high level of efficiency and qualityfactor in all positions of a timepiece, the effects of the force ofgravitational attraction must be minimised. For typical timepiecedimensions and using commercially available micro-magnets, it ispossible to generate magnetic and/or electrostatic forces greater thanthe force of gravity and than the torque acting on the component duringoperation. A system controlled by magnetic and/or electrostatic forcesis much less sensitive to gravity and thus to changes in the position ofthe watch, than conventional mechanical systems.

The invention is more particularly described with application tomagnetic forces. It is applicable in the same manner to the applicationof electrostatic forces, or even to a combination or mix of magnetic andelectrostatic forces. In particular, component 1 pivoting on an axis Dextends, in the direction of this axis D, between a first end 2 and asecond end 3 thereof. This first end 2 and second end 3 may be subjectto different treatment, for example, first end 2 may be subjected to anarray of magnetic forces, and second end 3 may be subject to an array ofelectrostatic forces or vice versa. The same end may also be subject,cumulatively, to an array of magnetic forces and to an array ofelectrostatic forces.

A first construction, seen in FIG. 10, consists in introducing polepieces, preferably formed by one or several micro-magnets, orrespectively by electrized masses, into the pivoting movements of thecomponent, adjusted to magnetise, or respectively electrize, an arbour,for example made of soft magnetic or respectively conductive material,comprised in the component, and thus to generate a magnetic orrespectively electrostatic attraction force, between bearings and thearbour of the component.

The preferred horological application described here encourages the use,in the version where forces of magnetic origin are used, of permanentmagnets to form the pole pieces used by the invention, but it is clearthat for other applications, notably static applications, it is alsopossible to employ electro-magnets. The use of the term “magnet” in thefollowing description generally indicates a magnetised pole piece.

On both sides of said first end 2 and second end 3 of component 1, thereare, on the one hand, means for guiding the pivoting of, or preferablyaccording to the invention, means for attracting first end 2, heldresting on a first pole piece 4 distinct from component 1 and, on theother hand, in proximity to a second pole piece 6, distinct fromcomponent 1, means for guiding the pivoting of the second end 3, orpreferably means for attracting said second end 3 to the second polepiece 6.

Component 1 is, at least in proximity to the first end 2 and the secondend 3 thereof, preferably made of a magnetically permeable and/orconductive material. In a particular embodiment of the invention, thismaterial is also magnetised and/or electrized.

Component 1 can move in a chamber 1A. A “pole piece” means a mass,which, at least in proximity to chamber 1A is made of a magneticallypermeable and/or conductive material, or, in a particular, preferredembodiment of the invention, in a magnetised and/or electrized material.The pole piece 4 or 6 does not form part of component 1, and is thuslocated at the periphery or in proximity to chamber 1A:

In a first embodiment, for example as seen in FIGS. 7, 9 and 13, thepole piece is separated from chamber 1A by a connecting piece whichincludes a support or stop surface for component 1. In FIG. 7, a firstpole piece 4 is thus separated from component 1 by a connecting piece18, which includes a first support surface 5 of this type, and a secondpole piece 6 is separated from component 1 by a connecting piece 19,which includes a second stop surface 7 of this type. In this variant,although they have no direct contact with component 1, the pole piecesinteract therewith, depending upon the particular case, via magneticand/or electrostatic attraction or repulsion: either one axial end ofcomponent 1 in axial direction D is magnetised or electrized, andcooperates with the closest pole piece, which is magnetically permeableor conductive under the action of a magnetic or electrostatic force, orconversely, one axial end of component 1 in axial direction D ismagnetically permeable or conductive, and cooperates with the closestpole piece, which is magnetised or electrized.

In another embodiment, seen in FIG. 6, this pole piece may include asurface forming one of the lateral surfaces of chamber 1A, which thefirst end 2 or second end 3 of component 1 is capable of coming inproximity to or in contact with. Preferably, when component 1 is amobile component pivoting about a pivot axis D, this surface of the polepiece is located in the continuation of said axis D. The magnetic and/orelectrostatic interaction occurs as in the preceding case, but withoutthe connecting pieces: component 1 is then in direct contact with one ofthe pole pieces.

Other embodiments concerns different variants at each end of component1: direct contact on one side, indirection repulsion or attraction forceon the other.

The invention is more specifically presented here in the preferred casewhere component 1 is subject to an array of attraction forces.Naturally, it is similarly possible to envisage a differential array ofrepulsion forces, holding component 1 on axis D via pole piecesdistributed annularly around this axis. However, although this variantoffers the advantage of allowing complete levitation of component 1, ithas the drawback of occupying significant annular volume annularlyaround component 1. Moreover, complete levitation no longer allows theperfect axial positioning of component 1 on axis D provided by theinvention, because of the support of component 1 at one of the endsthereof.

The first pole piece 4 and the second pole piece 6 are distinct fromcomponent 1 and are each located at the periphery of or in proximity tochamber 1A and are each made of at least partially magnetic orrespectively at least partially magnetically permeable material, and/orat least partially electrized or respectively at least partiallyconductive material. Component 1 is freely mounted in chamber 1A betweenpole pieces 4 and 6 so as to rest on a support surface in proximity toonly one of these pole pieces 4, 6.

FIG. 10 is a two-dimensional, axially symmetrical, schematic diagram ofan embodiment of component 1, for example a balance, in a version wherethe attraction forces are of magnetic origin: the longitudinal axisdefined by a first end 2 and a second end 3 of the component made ofmagnetisable or magnetic material, is located between two magnetic polepieces, particularly permanent magnets M_(A) and M_(B), the magneticpolarisation of which is directed in a direction z which is thetheoretical pivot axis of the component, and on which the longitudinalaxis of the component has to be aligned. The “arbour of the component”hereafter means a shaft-like part of component 1 which extends betweenfirst end 2 and second end 3 thereof. The arbour of component 1 may besupported either directly on this magnet or magnets, or by two jewelsinserted between the magnets and the arbour of the component, or bysurface treatment of the magnets. As seen in FIG. 7 of a particularembodiment, the arbour of component 1 may be made on a connecting piece18 fitted to the first pole piece 4. The second pole piece 6 may alsoinclude a connecting piece 19 of this type. These connecting pieces mustallow the magnetic field to pass. Their role is essentiallytribological, as regards the connecting piece which forms a supportsurface, and also to protect the pole pieces in the event of a shock.FIGS. 3, 4 and 6 illustrate the direct support of component 1 on a firstpole piece 4 and the possibility of intermittent support, which is alsodirect, for example during assembly or in the event of a shock, on asecond pole piece 6. The size and/or magnetic energy of the magnets andthe length of the arbour of the component are optimised to maximise theattraction force F_(m) between the arbour and one of the two magnetsM_(B).

According to the invention, the attraction force F_(m) is much largerthan the force of gravity F_(g), preferably in a ratio of at least 10 to1, and the arbour rests in a stable manner on only one of the twomagnets in all the positions of the timepiece or of the watch. The twoforces applied to the centre of gravity of the component are shown in adiagram in the case where F_(g) is opposite to F_(m).

A magnetic return torque acts on the arbour when the arbour deviatesfrom direction z: the geometry is optimised so that the magnetic returntorque is greater than the torque produced by the force of gravity andthan the torque which the component is allowed for stabilising theorientation of the arbour in direction z.

The magnetic force which acts on the magnetised arbour is proportionalto the magnetisation M_(axe) (r, z) thereof and to the gradient of themagnetic field H produced by the two magnets:

${\overset{\rightarrow}{F}}_{m} = {\mu_{0}{\int_{V_{axe}}\ {{\overset{\rightarrow}{r}}{{\overset{\rightarrow}{M}}_{axe} \cdot {\overset{\rightarrow}{\nabla}H}}}}}$

where integration occurs over the volume of the arbour V_(axe).

This relation optimises the size and/or magnetic energy of the magnetsand the geometry of the arbour of the component, in order to maximisethe attraction force between the arbour and one of the two magnets M_(B)in the case of FIG. 10. Consequently, the arbour only rests on one ofthe two magnets in all positions.

Since the attraction force is greater than the force of gravity and thanthe maximum force applied to the component, this configuration isstable.

The invention advantageously improves the efficiency of conventionalanti-shock solutions, which can thus advantageously be integrated inthis invention, because it guarantees that the arbour is returned to thecorrect position of equilibrium after a shock, which conventionalmechanical pivot devices cannot guarantee. The function of the uppermagnet is to stabilise the orientation of the arbour. The magnetictorque acting on the arbour is given by:

{right arrow over (C)} _(m)=μ₀ ∫{right arrow over (dr)}{right arrow over(M)} _(axe) ×{right arrow over (H)}

The magnetic torque is only zero if the arbour is oriented like thefield lines, and therefore in direction z. If the orientation of thearbour is disturbed and strays from direction z, the return torque C_(m)re-centres the arbour in the position of equilibrium.

FIG. 11 illustrates the magnetic force density on the arbour of thecomponent, in this case a watch balance, for real parameters. Theresulting magnetic force is F_(m)=10 mN, directed towards magnet M_(B),and therefore a larger order of magnitude than that of the force ofgravity, creating a greater torque than the maximum torque applied tothe component by the environment.

The invention has the advantage of largely confining the magnetic fieldinside the component arbour, and the field lines are practicallyparallel to direction z. The resulting magnetic force density for realparameters is shown in FIG. 11. Since the positive component, whichcorresponds to a force in the direction of M_(B), is greater, the netforce which acts on the balance is directed towards M_(B).

Since the force acting on the arbour only slightly depends upon theposition of the arbour on the support surface, with the field beingsubstantially homogeneous in the centre of the surface of the polepieces (notably magnets), the arbour is free to rotate around z withoutany additional friction. Therefore the dissipation of energy generatedby the oscillation of the component is greatly reduced, in the same wayas with mechanical friction: the efficiency and/or quality factor can beincreased in all positions.

In an alternative configuration, the arbour of the component may itselfbe a permanent magnet, either surrounded by pole pieces made ofmagnetisable material, or themselves magnetised, which then maximisesthe magnetic forces and torques present, and further minimises theinfluence of gravity.

In an alternative configuration, the arbour and/or board of thecomponent may be formed by a diamagnetic material, for example pyrolyticgraphite, and the pivot can be formed by several alternating magnets, toallow the diamagnetic levitation and positioning of the component.

Numerous advantages result from the features of the invention:

-   -   the efficiency and/or quality factor of the component is        identical in all positions of the timepiece, with variations of        less than 5%;    -   the efficiency and/or quality factor is increased in all        positions compared to with the use of conventional pivots;    -   in the case where the component oscillates, in particular a        balance, the oscillation amplitude thereof is increased and        identical in all positions.    -   friction and dissipation of energy are minimised as are torque        variations;    -   the number of components is limited compared to other solutions;    -   the invention is anti-shock by its very nature;    -   the system can be integrated in other magnetic elements.    -   the invention is easy to integrate in any type of timepiece or        watch, in particular a mechanical timepiece or watch, whether it        is simple or with complications, or in any portable scientific        apparatus or similar device.

A variant of the invention with non-aligned magnets may be of interestin certain cases, in particular for components for which the effect ofthe disturbance torque is negligible and for which a non-alignedconfiguration is simpler to achieve, because of the shape or position ofthe component.

For a generic component, it must also be considered that the inventionfurther advantageously allows the use of curved arbours: in such case,the two magnetic pole pieces (notably magnets) must have a differentdirection.

When the field lines of the two magnetic pole pieces (notably magnets)are not aligned, the system searches for a sufficiently stable positionof equilibrium. If the two directions are not too different, thelongitudinal axis of the component may remain within a dynamic regimeindefinitely, passing from an unstable position to another unstableposition. However, any misalignment has the effect of reducing themagnetic force applied to the component and, especially the returntorque. Consequently, stability is therefore lower than in the preferredcase of aligned field lines. When the component forms part of anoscillator, misalignment should be avoided, since it would introduce aradial magnetic torque having a disruptive effect on operation.

It is possible to envisage different variants of a magnetic pivotaccording to the invention, depending upon the composition and magneticproperties of the component: the fact that the arbour is made ofhomogeneous material means that the field lines can easily be closed.Slight non-homogeneousness in the longitudinal direction, associatedwith variations in density, section or concentrations of the alloy, maybe used to deliberately increase the asymmetry of the force and thusincrease the attraction force on one of the two sides. The material ofthe component, at least at the first and second ends, is preferablyferromagnetic, since a paramagnetic material would produce a force thatis too weak.

It is also possible to insert a amagnetic area, i.e. with very lowmagnetic permeability, between magnetic areas which are located at thefirst and second ends, if said ends are permanently magnetised. Thisarrangement provides a sufficiently large force and torque.

FIGS. 1 to 14 illustrate the embodiment of the invention.

The invention concerns a method for orienting a timepiece component 1 toguide the pivoting of said component, which is made of material that isat least partially magnetically permeable or respectively at leastpartially magnetic, and/or of material that is at least partiallyconductive or respectively at least partially electrized, wherein saidcomponent is pivotally mounted in a chamber 1A between a first end 2 anda second end 3 of said component 1.

According to the invention, on both sides of said first end 2 and secondend 3 two magnetic or respectively electrostatic fields are created,each tending to attract component 1 onto a pole piece 4, 6 and anunbalance is created between the magnetic or respectively electrostaticfields, around component 1 so as to create a differential in the forcesthereon to press one of the two ends 2, 3 onto a contact surface 5, 7 ofone of pole pieces 4, 6 and to hold the other of said ends 3, 2 at adistance from a contact surface 7, 5, comprised in the other pole piece6, 4. This unbalance between the magnetic or respectively electrostaticfields is created and exists around the air gap formed by the spacecomprised between these contact surfaces 5 and 7 which delimits chamber1A locally.

These magnetic or respectively electrostatic fields are asymmetrical inrelation to each other and of different intensity from each other.

The invention can be achieved, either by creating magnetic orrespectively electrostatic fields on pole pieces 4 and 6, or oncomponent 1 itself, or both on pole pieces 4, 6 and component 1.

When the magnetic or respectively electrostatic fields are created onpole pieces 4 and 6, the unbalance between the magnetic or electrostaticfields exists, according to the invention, regardless of whether or notcomponent 1 is present in the air gap: the fields are asymmetrical inrelation to each other, and of different intensity from each other, andaccording to the invention, the unbalance creating a differential in theforces on the component does not depend upon the position of saidcomponent in the air gap, but depends only on the asymmetrical fieldscreated on pole pieces 4 and 6.

When the magnetic or respectively electrostatic fields are created oncomponent 1 itself, they also are of different intensity at ends 2 and 3of component 1.

When the magnetic or respectively electrostatic fields are created bothon pole pieces 4 and 6 and component 1, they are sized such that theresultant thereof is asymmetrical, both on pole pieces 4 and 6 and ends2 and 3 of component 1.

In a first preferred variant, on both sides of first end 2 and secondend 3, two magnetic fields are created in substantially the samedirection and sense. This first variant applies in particular for acomponent whose arbour is conductive and magnetisable from the first end2 thereof to the second end 3 thereof, and this is how the magneticfield density is best concentrated around pivot axis D.

In another variant, on either side of first end 2 and second end 3 twomagnetic fields are created in substantially the same direction and inthe opposite sense. This other variant applies when there is electricaland/or magnetic discontinuity between the first end 2 and the second end3, for example if a component with very low magnetic permeabilityincludes only two magnetically permeable or magnetic half arbours at theends 2, 3 thereof. Naturally, the configuration of fields of the firstvariant is also applicable to this case. Another variant that can beachieved is where the component 1 is in a single piece, and wherediscontinuity is achieved by a particular fabrication method, forexample by surface treatment.

In a particular and preferred embodiment in the case where the componentis a balance or an oscillator member, the two magnetic fields having thesame direction are created on either side of the first end 2 and secondend 3.

In the variant illustrated by the Figures, according to the invention,the timepiece component 1 is oriented on a pivot axis D defined by thearrangement of the two magnetic fields and their respective pole pieces4, 6. On either side of the first end 2 and second end 3 on first polepiece 4 and second pole piece 6, a first magnetic field and a secondmagnetic field having opposite senses are created, each havingrevolution symmetry around pivot axis D and tending to attract component1 towards the pole piece 4, 6 thereof. The density of the first magneticfield in proximity to first end 2 is selected to be greater than that ofthe second magnetic field in proximity to second end 3, so as to attractthe first end 2 into contact with the first pole piece 4. The air gap Ebetween pole pieces 4, 6 is defined to be greater than the value of adetermined operating play J, at the distance of centres L between firstend 2 and second end 3.

The invention also concerns a device 10 for guiding the pivoting of atimepiece component 1, suitable, in particular, for implementing thisorientation method for guiding the pivoting of said component. Thiscomponent 1 must be made of material that is at least partiallymagnetically permeable or respectively at least partially magnetic,and/or of material that is at least partially conductive or respectivelyat least partially electrized, wherein said component is pivotallymounted in a chamber 1A between a first end 2 and a second end 3 of saidcomponent 1.

The guide device 10 includes, on both sides of the first and second ends2 and 3, on the one hand, means for attracting the first end 2 forholding said first end 2 resting on a first pole piece 4 and, on theother hand, in proximity to a second pole piece 6, means for attractingsaid second end 3 to said second pole piece 6.

According to the invention, this guide device 10 then includes, on bothsides of first end 2 and second end 3, at an air-gap distance E which isgreater, by the value of a determined operational play J, than thedistance of centres L between first end 2 and second end 3, a firstsurface of a first pole piece 4 and a second surface of a second polepiece 6.

These pole pieces 4 and 6, distinct from component 1, are arrangedeither each to be attracted by a magnetic or respectively electrostaticfield, transmitted by one or first end 2 or second end 3 of component 1,or, in a preferred manner, each to generate a magnetic or respectivelyelectrostatic field attracting one of first end 2 or second end 3 ofcomponent 1.

These magnetic or respectively electrostatic fields are of differentintensity from each other, at first end 2 and second end 3, such thatthe magnetic or respectively electrostatic forces being exerted oncomponent 1 at the two ends 2 and 3 thereof are of different intensity,so as to attract component 1 via only one of the two ends 2 and 3thereof, into direct or indirect contact on only one of the surfaces ofpole pieces 4 and 6.

In a particular variant, the first pole piece 4 and second pole piece 6are each moveable in a chamber between two stop members.

In a particular variant, the means for attracting first end 2 on the onehand, and the means for attracting second end 3 on the other hand, canmove along an axial direction D between stop members.

According to the invention, device 10 includes, at an air-gap distance Ewhich is greater, by the value of a determined operational play J, thanthe distance of centres L between first end 2 and second end 3, a firstsurface 5 of a first pole piece 4 and a second surface 7 of a secondpole piece 6.

These magnetic pole pieces 4, 6 are arranged either each to be attractedby a magnetic or respectively electrostatic field transmitted by one offirst end 2 or second end 3 of component 1, or each to generate amagnetic or respectively electrostatic field attracting one of first end2 and second end 3 of component 1, such that the magnetic orrespectively electrostatic attraction forces being exerted on component1 at the two ends 2, 3 thereof are of different intensity, so as toattract component 1 via one of the two ends 2, 3 thereof into direct orindirect contact on only one of surfaces 5, 7 of pole pieces 4, 6.

The magnetic or respectively electrostatic fields which are beingexerted in proximity to first end 2 and second end 3 are of differentintensity from each other and are asymmetrical.

According to the invention, the first pole piece 4 and second pole piece6 are each made of magnetic or magnetically permeable, or respectivelyelectrized or conductive material and are magnetic or respectivelyelectrized, if component 1 is not. First pole piece 4 and second polepiece 6 together define a pivot axis D, on which a longitudinal axis D1of component 1 is aligned, joining the first end 2 and second end 3thereof, when component 1 is inserted between first pole piece 4 andsecond pole piece 6.

According to the invention, the first pole piece 4, respectively thefirst end 2 generates, in proximity to first surface 5, a firstmagnetic, or respectively electrostatic field, along pivot axis D, whichtends to move first pole piece 4 closer to first end 2, and is of higherdensity than the density of a second magnetic or respectivelyelectrostatic field, along pivot axis D, generated in proximity tosecond surface 7 by second pole piece 6, or respectively second end 3.The second magnetic or respectively electrostatic field tends to movethe second pole piece 6 closer to second end 3, such that the first end2 is held in contact with first surface 5 and such that longitudinalaxis D1 of component 1 coincides with pivot axis D, and the second end 3then remains at a distance from the second surface 7.

Advantageously the air-gap distance E between first surface 5 and secondsurface 7 is dimensioned to ensure the determined operational play Jover the entire range of temperatures of use of guide device 10 and ofcomponent 1. This play is strictly positive, which excludes any clampingor friction fit. Preferably, the determined operational play J isgreater than or equal to 0.020 mm.

Preferably, the magnetic permeability of the material of component 1 isselected, and the magnetisation, as appropriate, of first pole piece 4and second pole piece 6 on the one hand, and/or component 1 on the otherhand, is fixed such that the first magnetic field and the secondmagnetic field exert on component 1 attraction forces that are at least30% greater than the gravitational force of attraction on component 1,and preferably five to ten times greater than the gravitational force ofattraction on component 1, in order to obtain the best behaviour whenthe timepiece is moving.

Likewise, the magnetic permeability of the material of component 1 isselected and the magnetisation, as appropriate, of first magnetic polepiece 4 and second magnetic pole piece 6, on the one hand, and/or ofcomponent 1 on the other hand, is fixed preferably such that the firstmagnetic field and the second magnetic field exert attraction torques oncomponent 1 that are more than ten times greater than the gravitationaltorque of attraction on component 1, in all positions thereof.

Preferably, the magnetic field density in proximity to the first surface5 and second surface 7 is greater than or equal to 100000 A/m.

Device 10 advantageously includes shielding means 20 made of softmagnetic materials, which are arranged to prevent the action of anymagnetic field with a radial component relative to pivot axis D, inproximity to first and second contact surfaces 5 and 7.

For example, this shielding means 20 includes at least one tubular part21, 22 centred on pivot axis D and surrounding the first pole piece 4and second pole piece 6, and at least the second end 3 of component 1 asseen in FIGS. 6, 7 and 8.

In the electrostatic variant, in a similar manner, the material ofcomponent 1 is selected, and the electrification, as appropriate, offirst pole piece 4 and second pole piece 6 on the one hand, and/orcomponent 1 on the other hand, is fixed such that the firstelectrostatic field and the second electrostatic field exert oncomponent 1 attraction forces that are at least 30% greater than thegravitational force of attraction on component 1 and preferably five toten times greater than the gravitational force of attraction oncomponent 1, in order to obtain the best behaviour when the timepiece ismoving.

FIGS. 3, 4 and 6 illustrate the direct support of component 1 on surface5 of first magnetic pole piece 4. FIG. 7 illustrates an indirect supportwhere the first end 2 of component 1 is resting on a surface 5 belongingto a connecting piece 18, which itself rests on the first pole piece 4or in immediate proximity thereto, so as not to reduce the effect of themagnetic or electrostatic attraction field, as appropriate, exertedbetween component 1 and pole piece 4. Likewise, where connecting pieces18, 19 are used, or surface treatments on surfaces 5, 7 of pole pieces 4and 6, the materials of these connecting pieces or of these treatments,the treatment methods, and sizing, especially in thickness, should beselected so as not to reduce the effect of the magnetic or electrostaticattraction field, as appropriate, exerted between first end 2 ofcomponent 1 and pole piece 4 on the one hand, and between the second end3 of component 1 and second pole piece 6 on the other hand.

Preferably, at least first surface 5 includes a hard coating or isformed by a hard surface of a connecting piece 18, which is insertedbetween first pole piece 4 and component 1. A similar connecting piece19 may be inserted between second pole piece 6 and component 1.

Device 10 further advantageously includes magnetic or respectivelyelectrostatic field loop means, between first pole piece 4 and secondpole piece 6, for example via an external clamp. FIG. 12 of a magneticvariant shows the first pole piece 4 magnetically integral with a firstarm 41 made of ferromagnetic material, the second pole piece 6magnetically integral with a second arm 42 made of ferromagneticmaterial, which is pressed onto a pole of a magnetic source 40, whichmay be a magnet or similar element, the first arm 41 being pressed ontothe other pole of said magnetic source 40. Shielding means 20 is theninserted between the magnetic source 40 and the field of cooperation ofcomponent 1 and pole pieces 4 and 6 in direction D. This configurationmay be applied to all of the cases considered: magnetically permeablecomponent 1 and magnetic pole pieces 4 and 6, magnetic component 1 andmagnetically permeable pole pieces 4 and 6, and magnetic component 1 andmagnetic pole pieces 4 and 6. This field transfer, which is show here aslateral, but which may occupy any other configuration in space, inparticular according to the volume available in a timepiece movement orin a timepiece, allows a field transmitted at a distance from this areato be transferred to pivot direction D. It offers the advantage ofenabling the field sources to be of much larger dimensions, regardlessof whether they are magnetic or electrostatic in nature.

In another embodiment, the attraction between pole pieces 4, 6 andcomponent 1 is electrostatic in nature. The design described here formagnetic attraction remains valid. However, it is more difficult toensure sufficient electrostatic charge to obtain electrostatic forcesand torques that are much greater than gravitational forces and torquesand derived from the mechanism with which component 1 cooperates.

In another embodiment, the attraction between pole pieces 4, 6 andcomponent 1 is electrostatic in nature. The notion of relativepermittivity or dielectric constant is then substituted for the notionof magnetic permeability, and the notion of electrostatic field issubstituted for that of magnetic field. The design of guide device 10 isentirely similar and is sized according to the permanent electrostaticfields set up between component 1 and pole pieces 4 and 6.

In this version, guide device 10 concerns the protection of a timepiececomponent 1 made of material that is at least partially conductive or atleast partially electrized at a first end 2 and at a second end 3.According to the invention, this guide device 10 includes, on both sidesof said first and second ends 2 and 3, at a greater air-gap distance, bythe value of a determined operational play J, than the distance ofcentres between first end 2 and second end 3, a first surface 5 of afirst pole piece 4 and a second surface 7 of a second pole piece 6,wherein the poles pieces 4, 6 are arranged either each to be attractedby an electrostatic field transmitted by one of first end 2 or secondend 3 of component 1, or each to generate an electrostatic fieldattracting one of first end 2 or second end 3 of component 1, such thatthe electrostatic attraction forces being exerted on component 1 at thetwo ends 2, 3 thereof are of different intensity, so as to attractcomponent 1 via one of the two ends thereof, into direct or indirectcontact on only one of surfaces 5, 7 of the pole pieces 4, 6. Theelectrostatic fields are of different intensity at first end 2 andsecond end 3.

According to a particular realisation, the first pole piece 4 and secondpole piece 6 can each move in a chamber between two stop members 41, 42,or 43, 44 respectively.

In short, in this embodiment, which relies on electrostatic forces andtorques, it is possible to use a conductive material either forcomponent 1, if pole pieces 4 and 6 are electrized and charged withsufficient energy, or for pole pieces 4 and 6, if it is component 1which is electrized and charged. This conductive material is polarisedby induction owing to the parts which are permanently charged. A similarvariant is obtained with the use of an insulating or semi-conductordielectric instead of a conductor. Polarisation is then limited to thesurface of the dielectric and the force and torque of attraction arelower than those developed when the material is conductive, but stillpermit this use for a watch.

It is also possible, in another embodiment, to combine the action ofelectrostatic forces and torques and magnetic forces and torques.

The invention further concerns a magnetic or respectively electrostaticpivot 100 including a timepiece component 1 of this type, made ofmaterial that is at least partially magnetically permeable orrespectively at least partially magnetic, and/or of material that is atleast partially conductive or respectively at least partiallyelectrized, wherein said component is pivotally mounted in a chamber 1Abetween a first end 2 and a second end 3 of said component 1.

Magnetic or respectively electrostatic pivot 100 includes a device 10for guiding the pivoting of timepiece component 1 including, at anair-gap distance E which is greater, by the value of a determinedoperational play J, than the distance of centres L between first end 2and second end 3, a first surface 5 of a first pole piece 4 and a secondsurface 7 of a second pole piece 6. These pole pieces 4, 6 are arrangedeither each to be attracted by a magnetic or respectively electrostaticfield emitted by one of first end 2 or second end 3 of component 1, oreach to generate a magnetic or respectively electrostatic fieldattracting one of first end 2 and second end 3 of component 1. Thesemagnetic or respectively electrostatic fields are of different intensityfrom each other, such that the magnetic or respectively electrostaticattraction forces being exerted on component 1 at the two ends 2, 3thereof are of different intensity, so as to attract component 1 via oneof the two ends 2, 3 thereof into direct or indirect contact on only oneof surfaces 5, 7 of pole pieces 4, 6.

Preferably, this magnetic pivot 100 includes a guide device 10 asdescribed in one of the variants hereinbefore. It further includes acomponent 1, comprising a substantially shaft-like portion made ofmaterial that is at least magnetically or respectively electrostaticallypermeable, or at least magnetic or respectively electrostatic, extendingbetween a first end 2 and a second end 3 and together defining alongitudinal axis D1. Guide device 10 includes access means forinserting component 1 into the air gap. Or guide device 10 can bedismantled into several parts that include means for cooperating witheach other and/or with a bridge 31 and/or a plate 30 to enable component1 to be assembled resting via the first end 2 thereof on a first part,which includes first surface 5 and first pole piece 4, prior to theassembly of a second part, which includes second surface 7 and secondpole piece 6.

In a particularly advantageous manner, as seen in FIGS. 8 and 9,component 1 has a spindle-shaped portion 8, rotating about longitudinalaxis D1, whose section decreases from the centre of gravity of component1 towards second end 3, so as to improve the magnetic field gradient inproximity to second surface 7, and to facilitate the centering of secondend 3 on pivot axis D.

When magnetic pivot 100 includes a component 1 belonging to anoscillator, advantageously component 1 is dynamically balanced, formaximum pivoting velocity, about longitudinal axis D1.

Preferably, the first end 2 of component 1 is arranged with a surfacehaving limited contact with first surface 5, the limited contact surfacebeing locally spherical or conical.

Advantageously, the first surface 5 includes a receiving surfacearranged to cooperate with first end 2. The receiving surface is hollowand locally spherical or conical.

In a preferred application to an oscillator, component 1 is a balancewhose pivot axis D coincides with longitudinal axis D1.

For maximum efficiency of the invention, if the shaft-like portion ofcomponent 1 is made of ferromagnetic or magnetised material, or includesareas made of this type of material, in the direction of longitudinalaxis D1 of component 1, it is advantageous for the rest of component 1to be made of amagnetic or magnetically inert material, for examplesilicon, or in a material having a relative magnetic permeability ofless than 1.0001 and made, in particular, in MEMS or LIGA or similartechnology, or even in an at least partially amorphous material. In theparticular case of a balance, at least the felloe and the arms arepreferably made of this type of material, as is the balance springassociated therewith. Thus there is no reciprocal interference betweenthe oscillator and the device 10 for pivotal guiding. Advantageously,all of the mobile components close to ends 2 and 3 of the component aremade in this type of amagnetic material.

An embodiment with a single-piece, silicon sprung balance including,either a magnetic arbour or arbour made of magnetically permeablematerial passing through the main axis of inertia, or two semi-arboursthat are magnetic or made of magnetically permeable material, aligned onboth sides of the balance on the same axis, is particularlyadvantageous.

Magnetic pivot 100 may adopt three configurations:

-   -   It includes a component 1 including a substantially shaft-like        portion made of magnetically permeable material, and the first        pole piece 4 and second pole piece 6 are each made of magnetic        material.    -   It includes a component 1 comprising a substantially shaft-like        portion made of magnetic material, and the first pole piece 4        and second pole piece 6 are each made of magnetically permeable        material.    -   It includes a component 1 comprising a substantially shaft-like        portion made of magnetic material, and the first pole piece 4        and second pole piece 6 are each made of magnetic material.

Naturally, it is possible to create a configuration with fields of adifferent nature at the two ends of component 1, magnetic at one end andelectrostatic at the other.

FIGS. 13 and 14 illustrate an advantageous embodiment, owing to itsgreat compactness, and the small total thickness which enables it to beused in a movement or timepiece of small thickness.

Pivot 100, which is illustrated here as magnetic, includes a dampingassembly.

Support surface 18A is a polished, concave, spherical sector made in ajewel 18. The jewel is pressed onto a permanent magnet 4, which developsa remanent magnetic field preferably higher than 1 Tesla. Opposite jewel18, relative to magnet 4, there is arranged a support jewel 43 with apolished convex profile. Jewel 18, magnet 4 and support jewel 43 areinserted together in a setting 40, made for example of beryllium copper.Preferably, jewel 19 and support jewel 46 are mounted in setting 40 bytightening or bonding, or by holding means ensuring a hold greater than1N. This setting 40 slides freely in a block 41, which has an opening 34for the passage of first end 2 of component 1, formed here by a sprungbalance assembly. This block 41 includes, in proximity to opening 34, aradial anti-shock member or a radial shock-absorber 32, formed inparticular by a shoulder that rotates around axis D.

The assembly is assembled such that the first end 2 of component 1 canmove in abutment in the convex dome 18A and such that the convex sectorof support jewel 43 is at the other end. This external block 41 acts asa stop member during shocks to component 1.

Preferably, the first end 2 of the component or balance 1 has acurvature, which is less than that of the concave calotte of jewel 18,so as to ensure contact on a single bridge. The concave curvature 18A ofjewel 18 decreases the air-gap distance between magnetic pole piece 6and first end 2 of component 1 and thus also forms a reservoir for theoil.

A similar assembly is placed at second end 3 of component 1. Supportsurface 19A is a polished, concave, spherical sector made in a jewel 19.The jewel is pressed onto a permanent magnet 6, which develops aremanent magnetic field preferably higher than 1 Tesla. Opposite jewel19, relative to magnet 4, there is arranged a support jewel 46 with apolished convex profile. Jewel 19, magnet 6 and support jewel 46 areinserted together in a setting 44, made for example of beryllium copper.This setting 44 slides freely in a block 45, which has an opening 35 forthe passage of second end 3 of component 1. Block 45 includes, inproximity to opening 35, a radial anti-shock member or radialshock-absorber 33, formed, in particular, by a shoulder that rotatesaround axis D. The assembly is assembled such that the second end 3 ofcomponent 1 can move in abutment in the convex dome 19A and such thatthe convex sector of support jewel 46 is at the other end. FIG. 4illustrates this end assembly at second end 3 which is damped by ashock-absorber formed by an elastic shock proof arm 50. This elastic arm50, as seen in FIG. 5, is fixed to a plate 30 or a bridge 31. It has afree end, which abuts on the convex calotte of support jewel 46, via atleast one contact surface and, in this preferred example, via threecontact areas 51, 52, 53 arranged in a triangle. Thus the force isperfectly distributed and the axial holding of the carrier assembly forsecond pole piece 6 is ensured. This type of elastic shock proof arm ispreferably mounted with pre-stress on the order of 0.5N.

It is clear that the same assembly may be positioned, symmetrically,abutting on support jewel 43, in proximity to the first end 2 ofcomponent 1.

Magnets 4 and 6 are preferably permanent Nd—Fe—B magnets, for instance<<Vacodym®>> by <<Vacuumschmelze GmbH>>.

The invention also concerns a timepiece movement 1000 including at leastone device 10 for pivotal guiding of this type, and/or at least onemagnetic and/or electrostatic pivot 100 of this type.

The invention also concerns a timepiece including at least one timepiecemovement 1000 of this type, and/or at least one device 10 for pivotalguiding of this type, and/or at least one magnetic or respectivelyelectrostatic pivot 100 of this type.

1. (canceled)
 2. A method for orienting a timepiece component to guidethe pivoting of said component, the component including a shaft-likeportion which includes at least areas in a ferromagnetic materialaccording to a direction of a longitudinal axis, wherein said componentis chosen including a ferromagnetic material at least on the level of afirst end and of a second end of said shaft-like portion according tosaid longitudinal axis, and, on both sides of said first and secondends, on a first and a second pole piece, respectively, a first and asecond magnetic field, respectively are created, in the same directionand in opposite senses, each tending to attract said component onto saidrespective pole piece, and an unbalance is created between said firstand second magnetic fields around said component, so as to create adifferential in the forces thereon in order to press one of said ends ofsaid component onto a contact surface of one of said pole pieces and tohold the other of said ends at a distance from a contact surface of theother pole piece, said unbalance between said magnetic fields beingcreated around an air gap formed by the space comprised between saidcontact surfaces, and wherein said magnetic fields are asymmetricalrelative to each other.
 3. The method for orienting the pivoting of atimepiece component according to claim 2, wherein said first magneticfield is created with an intensity different from the intensity of saidsecond magnetic field.
 4. The method for orienting the pivoting of atimepiece component according to claim 2, wherein said first magneticfield and said second magnetic field are created each having revolutionsymmetry about a common pivot axis, and said pole pieces are arrangedaround said pivot axis, and said first magnetic field is created with adensity in proximity to said first end which is greater than the densityof said second magnetic field in proximity to said second end, so as toattract said first end into contact with said first pole piece, andwherein the air gap between said pole pieces is greater, by the value ofa determined operational play, than the distance between said first endand said second end.
 5. A device for guiding pivoting of a timepiececomponent, said component including a shaft-like portion which includesat least areas in a ferromagnetic material according to a direction of alongitudinal axis, said component including a ferromagnetic material atleast on the level of a first end and of a second end of said shaft-likeportion according to said longitudinal axis, wherein said deviceincludes, at a greater air-gap distance, by the value of a determinedoperational play, than the distance between said first end and saidsecond end, a first surface of a first pole piece and a second surfaceof a second pole piece, wherein said poles pieces are each arranged togenerate a magnetic field attracting one of said first end or saidsecond end of said component, such that the magnetic attraction forcesbeing exerted on said component at the two ends thereof are of differentintensity, so as to attract said component via only one of said two endsthereof, into direct or indirect contact on only one of said surfaces ofsaid pole pieces, said unbalance between said magnetic fields beingcreated around said air gap formed by the space comprised between saidcontact surfaces, and wherein said magnetic fields are asymmetricalrelative to each other.
 6. The device according to claim 5, wherein saidfirst magnetic field has an intensity different from the intensity ofsaid second magnetic field.
 7. The device according to claim 5, whereinthe magnetic permeability of the material of said component, and themagnetization of said first pole piece and said second pole piece, aredetermined such that said first and said second magnetic fields exert onsaid component attraction forces that are at least ten times greaterthan the gravitational force of attraction on said component.
 8. Thedevice according to claim 5, wherein at least said first surfaceincludes a hard coating or is formed by a hard surface of a firstconnecting piece allowing the magnetic field to pass and insertedbetween said first pole piece and said component.
 9. The deviceaccording to claim 5, wherein at least said second surface includes ahard coating or is formed by a hard surface of a second connecting pieceallowing the magnetic field to pass and inserted between said secondpole piece and said component.
 10. The device according to claim 5,wherein said air-gap distance between said first surface and said secondsurface is dimensioned to ensure said determined operational play overthe entire range of temperatures of use of said guide device and of saidcomponent, and wherein said determined operational play is greater thanor equal to 0.020 mm.
 11. The device according to claim 5, wherein saidfirst pole piece and said second pole piece are each made of magneticmaterial and together define a pivot axis on which said longitudinalaxis of said component is aligned, when said component is insertedbetween said first pole piece and second pole piece.
 12. The deviceaccording to claim 11, wherein said first pole piece generates, inproximity to said first surface, a first magnetic field along said pivotaxis, which tends to move said first pole piece closer to said firstend, and which is of greater density than the density of a secondmagnetic field along said pivot axis, said second magnetic field beinggenerated in proximity to said second surface by said second pole piece,wherein said second magnetic field tends to move said second pole piececloser to said second end, such that said first end is held in contactwith said first surface, and such that said longitudinal axis of saidcomponent coincides with said pivot axis, and said second end remains ata distance from said second surface.
 13. The device according to claim5, wherein the magnetic field density in proximity to said first surfaceand to said second surface is greater than or equal to 100,000 A/m. 14.The device according to claim 5, further comprising shielding meansarranged to prevent the action of any magnetic field with a radialcomponent relative to said pivot axis, in proximity to said first andsecond contact surfaces.
 15. The device according to claim 14, whereinsaid shielding means includes at least one tubular part coaxial withsaid pivot axis and surrounding said first pole piece and said secondpole piece and at least said second end of said component.
 16. Thedevice according to claim 5, wherein said device includes magnetic fieldloop means between said first pole piece and said second pole piece. 17.The device according to claim 16, wherein said loop means include anexternal clamp, said first pole piece is magnetically integral with afirst arm made of ferromagnetic material, said second pole piece ismagnetically integral with a second arm made of ferromagnetic material,said second arm being pressed onto a pole of a magnetic source or of amagnet, said first arm being pressed onto the other pole of saidmagnetic source or said magnet, respectively.
 18. A magnetic pivotincluding a timepiece component made of material which is, or at leastpartially magnetically permeable with a magnetic relative permeabilitycomprised between 100 and 10,000, or at least partially magnetic andable to be magnetized so as to have a remanent field comprised between0.1 and 1.5 Tesla, wherein said component includes a shaft-like portionwhich includes at least areas in a ferromagnetic material according to adirection of a longitudinal axis of said component, and the material ofsaid component is ferromagnetic at least on the level of a first end andof a second end of said shaft-like portion according to saidlongitudinal axis, and said magnetic pivot includes a device for guidingthe pivoting of said timepiece component, said device including, at agreater air-gap distance, by the value of a determined operational play,than the distance between said first end and said second end, a firstsurface of a first pole piece and a second surface of a second polepiece, wherein said poles pieces are each arranged to generate amagnetic field attracting one of said first or second ends of saidcomponent, such that the magnetic attraction forces being exerted onsaid component at the two ends thereof are of different intensity, so asto attract said component via only one of the said two ends thereof,into direct or indirect contact on only one of said surfaces of saidpole pieces, and wherein said unbalance between said magnetic fields iscreated around said air gap formed by the space comprised between saidcontact surfaces, and wherein said magnetic fields are asymmetrical toeach other.
 19. The magnetic pivot according to claim 18, wherein saidmagnetic fields are of different intensity from each other.
 20. Themagnetic pivot according to claim 18, wherein said first magnetic fieldand said second magnetic each have a revolution symmetry about a commonpivot axis, and said pole pieces are arranged around said pivot axis,and said first magnetic field has a density in proximity to said firstend which is greater than the density of said second magnetic field inproximity to said second end, so as to attract said first end intocontact with said first pole piece, and wherein the air gap between saidpole pieces is greater, by the value of a determined operational play,than the distance between said first end and said second end.
 21. Themagnetic pivot according to claim 18, wherein, outside said shaft-likeportion, the rest of said component is made of amagnetic or magneticallyinert material.
 22. The magnetic pivot according to claim 18, whereinsaid guide device includes access means for inserting said componentinto said air gap, or is dismountable into several parts including meansfor cooperating with each other and/or with a bridge, and/or a plate, toenable said component to be mounted resting, via said first end thereof,on a first part including said first surface and said first pole piece,prior to the assembly of a second part including said second surface andsaid second pole piece.
 23. The magnetic pivot according to claim 18,wherein said component has a spindle-shaped portion rotating about saidlongitudinal axis, whose section decreases from the center of gravity ofsaid component towards said second end, so as to improve the magneticfield gradient, in proximity to said second surface, and to facilitatethe centering of said second end on said pivot axis.
 24. The magneticpivot according to claim 18, wherein said first end of said component isarranged with a limited contact surface with said first surface, whereinsaid limited contact surface is spherical or conical.
 25. The magneticpivot according to claim 18, wherein said first surface includes areceiving surface arranged for cooperating with said first end, whereinsaid receiving surface is hollow and locally spherical or conical. 26.The magnetic pivot according to claim 18, wherein said first pole pieceand said second pole piece are each made of magnetic material.
 27. Themagnetic pivot according to claim 18, wherein said component is abalance or a sprung balance wherein the pivot axis coincides with saidlongitudinal axis.
 28. The magnetic pivot according to claim 27, whereinat least a felloe and arms of said balance are made of magneticallyinert material, or silicon, or a material with very low magneticpermeability, and/or made using MEMS or LIGA technologies, or in an atleast partially amorphous material, and in that said balance includes,or an arbour made of magnetically permeable material, passing throughthe main axis of inertia thereof, or two semi arbours aligned on bothsides of said balance on the same axis, and made of magneticallypermeable material.
 29. A timepiece movement including at least onedevice for pivotal guiding according to claim
 5. 30. A timepieceincluding at least one timepiece movement according to claim 28.